The present invention relates generally to a shock absorbing structure, and more particularly to a shock absorbing structure for absorbing vibration generated by, for example, a motor in a driving mechanism of a scanner.
Referring to FIG. 3, a cross-sectional view of a prior shock absorbing structure and its related structure is shown. The shock absorbing structure is used for absorbing vibration generated by, for example, a motor in a driving mechanism of a scanner. As shown in FIG. 3, a cushion 1 made of elastic materials such as rubber has a central bore 9 in which a joint member 21 is disposed so that the joint member 21 and the cushion 1 define a gap. A screw 4 is driven through the joint member 21 and a plate 3 thus fixing the joint member 21 and the cushion 1 on the plate 3. Vibration of a motor is transferred to the cushion 1 through a motor supporting plate 5 thus being absorbed by the cushion 1. However, as shown in FIG. 4, when a lateral force F is exerted on the cushion 1 through the motor supporting plate 5, pressing a central portion of the cushion 1 against the joint member 21, elastic coefficient of the cushion 1 thus increases owing to such contact of the cushion 1 to the joint member 21. In other words, the pressed cushion 1 loses some elasticity but has more rigidity, which reduces shock absorption effect of the cushion 1.
For solving the above-mentioned problem that the cushion 1 can not be fixed well, an improved measure has been proposed. As shown in FIG. 5, a thin iron tube 31 is fixed on an inner sidewall of the cushion 1 to keep the gap defined between the cushion 1 and the joint member 21 unchanged. Therefore, when a lateral force F is exerted on the cushion 1 through the motor supporting plate 5, the central portion of the cushion 1 does not bend toward the joint member 21. Though such design can fix the cushion 1 well, it increases manufacturing cost and difficulties. And what is worse, it decreases shock absorption effect.